JP2008501376A - Medical device adapted to monitor limb muscle behavior of patients - Google Patents

Abstract

The present invention is related to a medical device for monitoring limb muscle behaviour in a patient, said limb corresponding to a leg or an arm, said medical device comprising: a moving unit (1) adapted to receive a first part of said leg or arm corresponding to the foot or to the hand (2), said moving unit (1) presenting at least one degree of freedom (11) according to which the moving unit (1) may move; a haptic device (6) adapted to receive a second part of said leg or arm corresponding to the foreleg or the forearm (5) respectively, and to measure in the form of an analogical signal the mechanical response of said second part to a movement of the moving unit (1); a set of electromyographic electrodes (4) able to measure in the form of an analogical signal the electrical activities in the muscle(s) of said leg or arm respectively; an analogical signal acquisition unit (9) able to acquire the analogical signals from the electromyographic electrodes and the haptic device (6) and converting said analogical signals into digital signals; a controller (8) able to process said digital signals and to control the moving unit (1). <IMAGE>

Description

  The present invention relates to a medical device that is preferably portable and to a method for monitoring and / or analyzing limb muscle behavior including patient muscle fibers and motor units.

  In particular, the present invention relates to medical devices and methods for dynamic analysis and / or monitoring of voluntary and unconscious movements of a patient's upper or lower limbs.

  Despite recent advances in the treatment of patients with central and / or peripheral nervous system disorders, neurologists and therapeutic professionals are able to perform spontaneous upper and lower limb movements clinically and subjectively in a test-dependent manner. We are still evaluating the unconscious movement, that is, the movement of the wrist joint. As a result, such clinical evaluation is not reliable.

  Therefore, the importance of medical devices or instruments that can help the examiner in diagnosis is clear.

  It is an object of the present invention to provide a medical device and method for systematically analyzing and / or monitoring the movement of a patient's limb.

  It is an object of the present invention to provide a medical device and method that provides reliable data.

  It is an object of the present invention to provide a medical device and method for easy use or implementation.

  It is an object of the present invention to provide a medical device and method for providing data that can be analyzed quickly by a skilled person.

The present invention is preferably portable medical for the analysis and / or monitoring of patient limb muscle behavior, preferably for simultaneous analysis of limb muscles tested during the patient's spontaneous and / or unconscious mechanical movements Relates to the device.
According to the present invention, the limb corresponds to the patient's leg, arm or neck, and the medical device includes:
A moving device adapted to receive the first part of the leg, arm or neck corresponding to the foot, forelimb, forearm, hand and / or head, the moving device providing at least one degree of freedom; A mobile device in which the mobile device can move accordingly;
-Receiving the leg, the arm or the second part of the neck corresponding to the front leg, upper leg, upper arm, forearm and / or neck, respectively, and mechanical response and / or movement of the second part to movement of the movement device; Haptic device adapted to measure dynamic responses in the form of analog signals;
A set of myoelectric electrodes capable of measuring the electrical activity of each muscle of the leg, arm or neck in the form of an analog signal;
An analog signal acquisition device capable of acquiring analog signals from myoelectric electrodes and haptic devices and converting the analog signals into digital signals;
A controller capable of processing the digital signal to control the mobile device;

  Similar to the mobile device, the haptic device may also include at least one degree of freedom.

  As used herein, “muscle” means the muscle as a whole and / or one or more muscle fibers and / or one or more units of motor of the muscle.

  Preferably, the moving device is driven by a motor under the control of the controller in the operating state.

  Preferably, the myoelectric electrode comprises a needle electrode and / or a surface electrode and / or a microelectrode. Preferably, the myoelectric electrode is a needle electrode and / or a surface electrode and / or a microelectrode.

  Preferably, the medical device according to the invention further comprises an amplification system for amplifying the analog signal measured by the electrodes.

  Preferably, the controller is configured to control or maintain the driving force of the motor in direction and intensity operating conditions, thereby controlling or maintaining movement of the mobile device in direction and intensity.

  The medical device is also adapted for passive monitoring of spontaneous patient movement.

  Advantageously, the moving device of the medical device provides a single axis of rotation about which the moving device has a rotation angle of at least about + 45 ° and at least about −45 ° and a specified maximum rotation relative to the haptic device. Can rotate at speed.

  Preferably, the maximum rotational speed is about 300 ° / second.

  Also advantageously, the moving device has a positional accuracy of about 0.1 mm. According to a preferred embodiment, the device further comprises a drug delivery device to the patient.

  Patient force feedback, which can be passive, static or dynamic, can be used for device movement.

  Further, in some embodiments, the device can be used to dynamically respond to patient forces.

The present invention also relates to a method for analyzing and / or monitoring limb muscle behavior using the portable medical device, wherein the limb is either a patient's leg, arm or neck. The method includes the following steps:
-Placing the first part of the patient's limb (each leg, hand, or neck) on the moving device;
-Placing the second part of the limb (foot, front leg, forearm, hand or head, respectively) on the haptic device in such a way that the main axis of the ankle, wrist, knee or neck respectively coincides with the main axis of the motor;
-Placing electromyographic electrodes at different locations on and / or in the muscle of the first part of the limb (each of the foot, forelimb, forearm, hand or head);
-The controller controls the exact direction and strength of the motor so that the moving device and the first part of the limb placed on it (foot, hand or neck, respectively) move with the correct direction and strength. Apply below;
-Measuring the mechanical response (direction and strength of movement) of the second part of the limb (each of the forelimb, forearm, hand or head) by means of a haptic device;
-Measure the electrical response of the first part of the limb (foot, front leg, forearm, hand or neck) with myoelectric electrodes at different positions along the first part of the limb (foot, front leg, forearm, hand or neck);
-Acquiring said mechanical and electrical response in the form of an analog signal by means of an acquisition device;
-Converting said analog signal into a digital signal;
The digital signal is processed by a controller;

  The method also applies a precise direction and amplitude displacement to the moving device and the first part of the limb placed thereon (foot, hand or neck) under the control of the controller, and the haptic device allows the limb to be moved. A step of measuring the force generated in the second part (front leg, forearm, hand or head) may be included.

  As already specified above, “muscle” means a muscle and / or muscle fiber as a whole and / or a motor unit of said muscle.

  Preferably, the analog signal is acquired with respect to time and processed to have limb movement monitoring over time.

  The invention also relates to the use of the medical device and / or the method as a tool for monitoring a patient's spontaneous and unconscious limb movements.

  The present invention also relates to the use of the medical device and / or method as an indirect tool to provide physical data for assessing the stage of patient recovery.

  Another object of the invention is the use of the medical device and / or the method for investigating the effect of a drug in a patient.

  Note that the medical device and method according to the present invention provides data corresponding to intermediate results on limb muscle behavior that cannot be made by itself, thereby allowing the doctor or surgeon to make decisions about the diagnosis and necessary treatment. There must be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 represents one embodiment of a medical device such as that used to monitor motor unit and arm muscle behavior according to the present invention.

  Figures 2a and 2b represent side and top views, respectively, of a medical device (moving device + tactile device) as used in the preferred embodiment of the medical device.

As shown in FIG. 1, a medical device according to the present invention is a portable medical device including:
A mobile device 1 capable of moving according to at least one degree of freedom;
A motor 7 for driving the moving device 1 given the main rotary shaft 3;
A haptic device 6 having at least one degree of freedom and capable of measuring mechanical movements in the amplitude and direction of the object by haptic contact of the object using haptic technology;
A set of myoelectric electrodes 4;
A signal amplifier 10;
A signal acquisition device 9; and a controller 8 that drives the motor 7 with calibrated movement and has signal processing capability.

  In this embodiment, the moving device provides a rotating shaft 11 that coincides with the rotating shaft 3 of the motor 7. Thus, the moving device can rotate around its axis of rotation 11 with respect to the haptic device 6 with the correct rotation angle α and the correct rotation speed or speed (under the control of the controller 8).

  The mobile device 1 can also be translated. Perhaps the haptic device 6 can also be rotated and / or translated.

  The haptic device 6 of the present medical device can measure force using haptic technology.

  The principle of the medical device is to induce a mechanical perturbation of the patient's upper or lower limb, preferably by the moving device 1, and to measure the mechanical and electrical response of the upper or lower limb muscles to the perturbation.

  Medical devices have been adapted to study limb muscles and / or their muscle fibers and / or motor units as a whole.

In operating conditions, a method for monitoring movement of a limb such as an arm as shown in FIG. 1 using the medical device includes the following steps:
The arm is placed against the medical device so that the hand 2 is on the moving device 1, the forearm 5 is on the haptic device 6 and the wrist main axis coincides with the main axis 3 of the motor 7;
-Once the arm is correctly placed, place the electromyographic electrode 4 along the arm, preferably along the forearm 5 at different locations on the patient's muscle or skin;
The controller 8 causes the motor 7 to drive the mobile device 1 and thus the hand 2 according to a movement (or (different) movement pattern) with the correct direction and amplitude;
The mechanical response in amplitude, direction and force of the patient's forearm 5 is measured by the haptic device 6;
The electrical response (electrical activity) is measured simultaneously at different positions along the arm, preferably along the forearm 5 by the electrode 4;
-Obtain electrical and mechanical responses in the form of analog signals;
-Converting said analog signal into a digital signal;
The controller 8 processes the digital signal to provide data on patient movement that can be interpreted by a skilled person.

  The medical device may include four different myoelectric electrodes that can be inserted into four forearm muscles (i.e., heel side carpal flexor, heel side carpal extensor, brachial radius, and ulnar carpal flexor). The (active) surface electrode can be fixed to the skin at the level of the heel side carpal flexor and the heel side carpal extensor.

  Perhaps the motor shaft can be easily and quickly moved in more than one plane.

  One advantage of this medical device is that it is configured and dimensioned so that it is portable and that it is at the patient's bedside in different possible positions (horizontal, vertical, or seated position). It can be used for. Thus, the medical device is extremely comfortable for the patient and can be used in extreme conditions (eg in case of emergency).

  The medical device and method according to the present invention offers a wide range of applications.

  Discharges of individual muscle fibers or single motor units can be identified and analyzed in different states of forelimb, forearm or neck joint impedance.

  In order to analyze the control mechanism by the nervous system regarding the behavior of muscle fibers and motor units during mechanical stretching of the muscle, the medical device, for example, the central nervous system (preferably the motor cortex or spinal cord) or the peripheral nervous system (especially the nerve ) Can be combined with a source of external stimulation (preferably electrical or magnetic stimulation).

  As already disclosed above, the present medical devices and methods can be used as a tool to investigate the mechanisms of neural control of wrist movements in patients with central and / or peripheral nerve disease.

  Also, for example, the medical device and method can be used to analyze the characteristics of the frequency band and muscle coherence of pathological hand tremors in different impedance conditions under different inertial conditions. This analysis can provide indirect information useful for establishing neurodifferential diagnosis.

  The medical device can be used as a clinician's tool to help establish a differential diagnosis of psychogenic tremor.

  The medical device and method can be used to test the effects of candidate drugs on limb tremors, in particular hand tremors, such as essential hand tremors or hand tremors associated with Parkinson's disease.

  Another possible application of the medical device is its use as a tool to accurately assess the mechanism of cerebellar dysmetria recovery and then determine the stage of recovery achieved by the patient after cerebellar stroke. In that sense, the medical device and method can indirectly help a physician to improve a patient's nerve rehabilitation.

  The medical device and method can be used to objectively assess the condition of the wrist joint during neurosurgical procedures in patients with Parkinson's disease. From that perspective, the medical device and method can indirectly help a doctor to perform more effective deep brain stimulation (eg, nerve stimulation of the subthalamic nucleus).

  The medical device can also be used as a tool to analyze the control of a patient's hand after hand joining.

  The medical device can also be used to test a prosthesis or an orthosis such as a heat deformable prosthesis and / or an orthosis.

  Rehabilitation of the patient's limb after an accident is also a possible application of the medical device.

  As indicated above, one of the main advantages of the medical device compared to the prior art is that it provides objective data.

  However, the medical device and method according to the present invention provides data corresponding to intermediate results on limb muscle behavior that cannot be made by itself, thereby only allowing a doctor or surgeon to make a decision on the necessary treatment. It should be understood.

  However, in contrast to previously known devices, the device according to the present invention has surface EMG activity and combined with analysis of muscle fibers and / or muscle motor units without inducing mechanical movement in the patient's limb. Analysis of intramuscular activity can be combined.

  Furthermore, the device can be used for analysis and / or monitoring of various vibrations, spontaneous or unconscious movements of the patient.

  Furthermore, the device according to the invention is used for analysis and / or monitoring of the effects of high-frequency vibrations on limb muscle behavior, in particular the motor units of these muscles or muscle fibers from different muscles, in particular continuous muscle fibers. Can do.

  Advantageously, the device can be used to maintain a constant strength at a predetermined position on the patient's arm, leg or neck and thus record their intramuscular EMG related activity. This analysis is particularly useful for recording movements induced by muscle units of different positions after automatic movement from one position to another.

  The medical device according to the invention is particularly ergonomically adapted to the patient's limb, such as the neck, hand, arm, foot or leg.

  Finally, retro-control loops can be introduced in controlling various elements of the device through real-time intramuscular activity analysis and / or monitoring.

  The device according to the invention also allows an immediate adaptation of the vibration frequency according to the limb muscle behavior.

  Another possible application of the medical device is tetanus stimulation. More precisely, the medical device may be used to analyze the frequency of muscle contraction (detected by an active electrode placed on the skin, or an intramuscular electrode, or both). These frequencies can be used to study the behavior of motor units known as slow motor units and this behavior can be compared to the behavior of motor units known as rapid motor units.

  In addition, the medical device allows an immediate calculation of the stiffness index from the torque / position curve by linear regression measurement. This technical property represents a substantial advantage in the pharmacological evaluation of new drugs that interact with the central nervous system and the prospect of search for possible changes in the articulated impedance induced by drugs. This stiffness can be calculated very quickly.

  Finally, the device according to the invention is adapted to identify frequencies in muscle motor units and which dynamic perturbations can induce different forces according to the position of the arm, leg or neck.

  The device is also applied to simultaneously detect joint stiffness and spontaneous or unconscious movements of patients suffering from dystonia movement with extra cone stiffness.

  According to the last embodiment of the invention, the device according to the invention can be programmed to induce different continuous mobilizations at different vibration frequencies according to a rehabilitation program that follows without any external influences. it can.

Examples of Special Embodiments According to a preferred embodiment of the present invention, the medical device presents the following technical features:
-Four differential amplifiers with an amplification factor of 1000 (for example, those manufactured by Xltek company Canada);
-Sterile concentric needle electrode 30G (eg Medtronic company, (sold by Skovland, Denmark)
Two surface-active electrodes with pre-amplification and the filters contained therein (amplification factor of 1000; filter 20-450 Hz, for example manufactured by Delsys DE-2.3);
-One analog acquisition device;
-One personal computer; and-shown in FIGS. 2a and 2b with one degree of freedom (rotation axis with reference number 11) with force return or force feedback acting to generate any dynamic behavior A moving device coupled to a haptic device.

The characteristics of the mobile device are as follows:
-Position accuracy: 0.1 mm at the level of the fingertip on the haptic device;
-Nominal torque: 4 Nm;
-Peak torque: 20 Nm;
-Maximum rotation speed: 300 degrees / second;
-Range of movement: +45 to -45 degrees.

1 represents one embodiment of a medical device as used to monitor motor unit and arm muscle behavior according to the present invention. 1 represents a side view and a plan view of a medical device (moving device + tactile device) as used in a preferred embodiment of the medical device.

Claims (10)

A medical device for monitoring limb muscle behavior of a patient, wherein the limb corresponds to a leg, arm or neck, and the medical device includes:
-A mobile device (1) adapted to receive the first part of the limb (leg, arm or neck) in correspondence with the second part of the limb (foot, front leg, forearm, hand (2) or head); A moving device (1) in which the moving device (1) gives at least one degree of freedom and the moving device (1) can move accordingly;
-Receiving the first part of the limb (leg, arm or neck) corresponding to the second part of the limb (front leg, upper leg, upper arm, forearm (5) or neck), respectively, and said first part with respect to the movement of the mobile device (1); A haptic device (6) adapted to measure the mechanical response of two parts in the form of an analog signal;
A set of electromyographic electrodes (4) capable of measuring the electrical activity of the muscles of the limbs (leg, arm or neck, respectively) in the form of analog signals;
An analog signal acquisition device (9) capable of acquiring an analog signal from the myoelectric electrode and the haptic device (6) and converting the analog signal into a digital signal;
A controller (8) capable of processing the digital signal and controlling the mobile device (1);   2. The medical device according to claim 1, wherein the moving device is driven by a motor (7) under the control of a controller (8).   The medical device according to claim 1 or 2, wherein the myoelectric electrode is a needle electrode and / or a surface electrode.   The medical device according to any one of claims 1 to 3, comprising four myoelectric needle electrodes and two myoelectric surface active electrodes.   The medical device according to claim 1, wherein the myoelectric electrode is a microelectrode.   The moving device (1) provides at least one axis of rotation (11) around which the moving device (1) has a rotation angle (α of about + 45 ° to about −45 ° with respect to the haptic device (6). And the medical device according to any one of claims 1 to 5, wherein the medical device can rotate at a specified maximum rotation speed.   The medical device according to claim 6, characterized in that the maximum rotational speed of the moving device (1) is about 300 ° / sec.   The medical device according to claim 6 or 7, characterized in that the moving device (1) has a positional accuracy of about 0.1 mm.   9. The medical device according to claim 1, further comprising an amplification system for amplifying an analog signal measured by the electrode (4).   3. Medical device according to claim 1 or 2, characterized in that the controller maintains the driving force of the motor (7) in direction and intensity, thereby maintaining the movement of the moving device (1) in direction and intensity.

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